It’s been 25 years since the romantic comedy “Groundhog Day” hit theaters. Now a bona fide classic, a big part of why the film has endured is Bill Murray’s commitment to authenticity, his co-star Andie MacDowell told TheWrap in a recent interview.

“He asked me to really slap him,” MacDowell said of the multiple times the film features her character Rita striking him, after Murray’s glib Phil Connors attempts to woo her. “It’s hard to hit someone that many times!”

Of course, Murray plays a man who finds himself stuck repeating the same day over and over again. And his dedication to the role kept MacDowell on her toes constantly, she recalled.

“Bill is so funny. He’s a comic genius,” the actress said. “Listening and reacting to Bill — because Bill is not the same in every take — so listening and react. His nature is to improv and make it his own every take. It was mostly fresh. I had to really be in the scene and just listen to him.”

Casting MacDowell opposite Murray was a matter of balancing the energy he would bring to the role, she said of the making of the 1993 film. Producer Trevor Albert looked at talented comediennes for the part of Rita, but found the effortless grace MacDowell brought to the part was more suited to Rita’s warmth and spirit.

“If you put him with somebody who tries to match that, fighting for airtime and screen time, it’s challenging,” Albert told TheWrap. “Her strength doesn’t come in her repartee and her comedy, it comes in her grace and her confidence and her intelligence.”

“The way I go about comedy is to try and be a real character. The reason I was funny was because I was honest; I was purely honest,” MacDowell said about playing news producer Rita. “That was in there, to come from a very real, believable, honest place, and not try and be too big or too broad or colorful to be believable.”

After his perfect co-star was cast, Murray’s next challenge was to make his character sarcastic, blasé and cynical — and still make him likable. Phil Connors shows disdain at his job, looks down on the simpletons of Punxsutawney, Pennsylvania and likens himself to a god. But he delivers his lines with a tossed off detachment, never spite or malice. And as he grows into a better person, he doesn’t lose that witty repartee that made him a lovable grump in the first place.

“He’s a jerk but he makes you laugh, even though you pull for him not to be a jerk,” MacDowell said.

“This is part of his magic,” added Albert. “He’s got that everyman quality, but he can still pour a beer on your head and people are still laughing about it.”

Screenwriter Danny Rubin agreed, telling TheWrap, “No one can do Bill better than Bill… I didn’t write it to be a broadly nasty person. If anything I just wrote him to be a normal, average person just stuck in a circumstance.” Director Harold Ramis, who died in 2014, eased the writer’s concerns over casting Murray. “He said, ‘Don’t worry. This is what Bill Murray can do. He can be that nasty and still make you like him.’ He reassured me about that. And he was correct,” recalled Rubin.

As for those very real slaps Murray voluntarily endured during filming, here’s a look back on how they played out on the big screen:

'Groundhog Day' and 9 Movies That Repeat the Same Day Over and Over (Photos)

“Groundhog Day” turns 25 years old this month, and its ingenious concept of imagining what a man would do if he was stuck living the same day over and over again has inspired filmmakers to experiment with this gimmick. You know you have something special when people describe your movie by saying, “It’s like ‘Groundhog Day’ crossed with X.” All of these movies have variations on the time loop storyline, though with all of the repetition, you may only want to watch them once.

Columbia Pictures Corporation

“Source Code” (2011)

Jake Gyllenhaal wakes up in someone else’s body eight minutes before a terrorist attack blows up the train he’s riding on. It’s his job to use that time to find the terrorist and stop the attack. The movie’s first eight minutes are its best when he realizes that he’s living someone else’s final moments. Director Duncan Jones uses the sci-fi set up as a parable for the frustration of being used as a tool and the nature of free will within each alternate reality.

Summit Entertainment

“Edge of Tomorrow” a.k.a. “Live. Die. Repeat.” (2014)

This is one of Tom Cruise’s most underrated roles. We watch him die on an endless loop as he tries to learn how to win in a war against aliens, with each of his lives playing out like a video game in which he gains experience and gets closer to winning. But its charm comes from a sardonic sense of humor and Cruise’s relationship with a hard-nosed soldier played by Emily Blunt. In the end, she ends up killing him in training more times than the aliens do.

Warner Bros. Pictures

“50 First Dates” (2004)

Leave it to Adam Sandler to make another rom-com aping a “Groundhog Day” premise. In this one, Drew Barrymore only thinks she’s living the same day over and over because she has an affliction in which she can’t remember the previous day, but it doesn't Sandler from trying to win her over. Short-term memory loss is a real thing, but not Barrymore’s specific affliction.

Columbia Pictures Corporation

“Primer” (2004)

One of the more creative indie time travel stories you’re likely to see, Shane Carruth’s lo-fi thriller is a densely plotted science fiction story about two entrepreneurial inventors who accidentally invent a device that allows them to travel back in time for a few hours at a time. Carruth keeps us in the dark as to what they’ve actually invented until well into the film, and it maintains its tension as it evolves into a character study of these two men trying to double cross the other.

THINKFilm

“Naked” (2017)

It’s “Groundhog Day” with no clothes! Phil Connors at least didn’t have to relive the same humiliation Marlon Wayans does, where he wakes up naked hours before his wedding day and has to repeat things over and over until he gets things right. The film is actually a remake of a Swedish film from 2000.

Netflix

“Before I Fall” and “Happy Death Day” (2017)

What if “Groundhog Day” was about a mean girl? Zoey Deutch stars as a San Francisco teen with a “perfect” high school life until she’s killed in a car accident. When she repeats the same day of her death, she starts to reassess her relationships and unravel the mystery around her accident. “Happy Death Day” has an almost identical premise but plays up the horror elements more so than the YA drama.

Open Road Films/Universal Pictures

“Run Lola Run” (1998)

Tom Tykwer’s action classic takes the time looping premise and turns it into a kinetic, real-time thrill ride. The title character Lola goes on a 20-minute dash as repeated several times, with each time depicting slight changes in the story that invoke ideas about parallel realities and moral choice.

Sony Pictures Classics

“12:01” (1993)

The short story on which “12:01” is based actually pre-dates “Groundhog Day” by nearly 20 years. It’s about a man caught reliving the worst day of his life when his wife is shot and killed. After receiving an electrical shock at midnight, he relives the previous day and finds that things get worse.

New Line Television

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Haven’t I seen this movie before?

“Groundhog Day” turns 25 years old this month, and its ingenious concept of imagining what a man would do if he was stuck living the same day over and over again has inspired filmmakers to experiment with this gimmick. You know you have something special when people describe your movie by saying, “It’s like ‘Groundhog Day’ crossed with X.” All of these movies have variations on the time loop storyline, though with all of the repetition, you may only want to watch them once.